This invention relates to open-end wrenches, and more particularly to wrenches of this type which are capable of a ratchet-like action when engaged with an hexagonal nut or fastening.
Numerous open-end ratchet-type wrenches have been proposed and produced in the past, to facilitate the tightening and loosening of nuts and bolts especially where these are located in awkward places or cramped areas. Some representative wrenches of this type are shown and described in the following U.S. Pat. Nos.: 749,134; 770,574; 1,015,504; 1,183,371; 1,305,571; 3,165,015; and 3,901,106.
These patented devices have not come into universal use for various reasons. Either the constructions were too complicated and costly to produce, or else too large or bulky, or else limited as to their scope. For example, the wrench of U.S. Pat. No. 770,574 is operative only in connection with square nuts or square bolt heads, and has no utility for hexagonal fitments.
Most of the above patented devices employ pivotal mountings for their movable jaws, and such mountings are often yieldable or lacking in strength whereby the wrench will lose its usefulness after a period.
The last four of the patented devices in the above listing are characterized by multiple components, increased bulk and complexity, and difficulty of manufacture whereby their wide acceptance by the trade did not occur. The wrench of U.S. Pat. No. 749,134 employs an outboard spring 12 which increases the bulk or size of the jaw assemblage, and is subject to distorting forces that can defeat its operation. Also, this wrench depends on the strength of a single pivot pin for proper functioning.
U.S. Pat. No. 1,015,504 shows a wrench which cannot be slid edgewise onto a nut or bolt head but instead requires that it be applied laterally and in an axial direction toward the end of the hexagonal part.